STRUCTURE, GROWTH AND CELL-PROLIFERATION OF HUMAN OSTEOSARCOMA AND MALIGNANT FIBROUS HISTIOCYTOMA XENOGRAFTS IN SERIAL TRANSPLANTATION IN NUDE-MICE

Tumour specimens from one patient with osteosarcoma and one with malig nant fibrous histiocytoma were transplanted in serial passages in nude mice. Structure, growth and cell kinetics of the xenografts were stud ied in order to assess the validity of the two tumour models. Cell pro liferation was analysed using in vivo labelling with the thymidine ana logue iododeoxyuridine (IdUrd) and the IdUrd labelling index (LI) was determined by immunohistochemistry. The DNA index (DI) was examined by flow cytometry. The c-myc oncoprotein expression was studied by immun ohistochemistry. More intense proliferation was observed in the periph eral parts of the tumours. There was no correlation between tumour gro wth and cell proliferation in the two tumour groups. Stability of the tumour models was indicated by low intrapassage and interpassage varia tions of DI, LI, and volume doubling time, and also by retained histop athological characteristics and c-myc staining patterns of donor patie nts' tumours during serial transplantation.